Process for breaking petroleum emulsions



atented Earn. a, ll

rnoonss run a l a rn'raopnmn l SIGNS No Drag. Application July 7, 19411,

Serial No. 401,383

3 Claims.

This invention relates primarily to the resoluan of petroleum emulsions.

One object of my invention is to provide a Jvel process for resolving petroleum emulsions the water-in-oil type, that are commonly relrred to as cut oil, roily oil, emulsified 1, etc., and which comprise fine droplets of iturally-occurring waters or brines dispersed I. a more or less permanent state throughout le oil which constitutes the continuous phase of le emulsion.

Another object is to provide an economical and mid process for. separating emulsions which ave been prepared under controlled conditions 'om'mineral oil, such as crude petroleum and :latively soft waters or weak brines. Controlled nulsification and subsequent demulsification nder the conditions just mentioned is of siglficant value in removing impurities, particulrly inorganic salts, from pipeline oil.

The composition of matter herein described, rat is used as the demulsifying agent of our recess, is obtained by blowing or oxidation of ater-insoluble oxyalkylated triricinolein, parcularly oxyalkylated castor oil, and more spe- Uically, oxyethylated castor oil. The manner of lowing or oxidizing such products is substantialr the same as is employed to oxidize or blow astor oil, ricinoleic acid and the like.

It is well known that oxidized oils can be obained from castor oil, ricinoleic acid and varius derivatives of ricinoleic acid, such as monoicinolein, diricinolein and polyricinoleic acids. hey are produced by the common practice of lowing or oxidizing castor oil and similar fatty ils or acids, particularly'non-drying unsaturated atty oils, by means of a gaseous medium, such s air, oxygen, ozone, or ozonized air. ,The gaseus medium, such as air, may be moist or dry and he oindation may take place in the presence or .bsence of a catalyst. The catalyst may be of a metallic type, such as lead ricinoleate, cobalt icinoleate, manganese ricinoleate, etc.; or it may '9 of the organic type which produces peroxide, uch as alpha pinene, linseed, oil, etc. Oxidaion may take place at atmospheric pressure or uperatmosphere pressure, i. e.,. pressures up to longer time periods being employed generally when the temperature is just slightly above the boiling point of water and when oxidation is with air at atmospheric pressure.

r including 200 pounds gauge pressure, and at .ny temperature slightly above the boiling point.

|f water, for instance, 120 C. up to any temrerature which does not produce undue decomaosition by pyrolytic reaction.

The time oi blowing may be fairly brief, for extmple, 8-10 hours; or it may be quite extensive, or instance, as long as l0--l21e days, the

1 One method of preparing drastically oxidized castor oil is described in U. S. Patent No. 2,023,979, dated December 10, 1935, to'Stehr. Also see U. S. Patent No. 2,183,487. dated December 12, 1939, to Colbeth.

Thus, the same conventional procedure or procedures employed for the oxidation of castor oil or similar compounds is equally suitable for the blowing or oxidation of water-insoluble oxyalkylated triricinoleins. In most instances the period of oxidation is apt to be much longer. For instance, it may require two or three times as long under similar conditions to blow or oxidize oxyalkylated triricinoleins to the same degree of oxidation as is required for castor oil. Inversely,.ii one attempts to obtain the same degree of oxidation within the same period of time, the step of oxidation itself must be more vigorous.

It is well known that the exact composition of ordinary oxidized castor oil is not known. This has been a matter of comment from time to time in the literature, including the patent literature dealing with arts in which blown castor oil is contemplated. However, it is obvious that the nature of the products obtained by the oxidationof oxyalkylated triricinolein must be significantly difierent from those obtained by the oxidation of castor oil. It is obvious that oxidized water'- insoluble oxyalkylated triricinolein must be of a diflerent nature than ordinary oxidized castor oil.

It is well known that if triricinolein, preferably in the form of castor oil, is treated with an oxyalkylating agent, particularly ethylene oxide, propylene oxide, butylene oxide, g ycidol, or the like, and it one employs a large molecular proportion of the oxyalkylating agent for each mole of occurrence of the ricinoleyl radical, that one can convert castor oil into a water-soluble product. The conventional procedure is well known, and generally speaking, involves nothing more or less than heating castor oil in the presence of successive small amounts of alkylene oxide or the like, under comparatively low pressures and fairly low temperatures, and usually in the presence of an alkaline catalyst, as, forexample, sodium ricinoleate. The temperatures employed are generally above C. and below 200 (7. The pressures employed are generally above 100 pounds gauge and below 300 pounds gauge pressure. Sometimes oxyalkylation is conducted in a continuous manner by introduction ofthe ethylone oxide in a gaseous state. More frequently, and most conveniently, the oxide is introduced in a liquid form in a comparatively small amount, for instance, 300 pounds of castor oil and pounds of ethylene oxide, along with approximately one pound of sodium ricinoleate. Reaction is allowed to take place under pressure in the manner above described until all the ethylene oxide is absorbed Another portion of ethylene oxide is added, and the procedure repeated until water solubility is obtained. Not infrequently as many as 30 pound moles of the oxyalkylating agent are employed for one pound mole of triricinolein, in order to obtain complete water solubility. Needless to say, ethylene oxide promotes solubility in lower molecular proportions than propylene oxide or butylene oxide. Furthermore, ethylene oxide is preferable, due to its greater reactivity.

We have found that if one oxyalkylatcs triricinolein with any of the oxyalkylating agents indicated, particularly ethylene oxide, to a point definitely short of water solubility, and if one employs such water-insoluble oxyalkylated triricinolein or triricinoleins instead of triricinolein in a conventional oxidation or blowing operation of the kind conventionally employed in connection with castor oil, one obtains a new composition of matter which is particularly efiective as a demulsifier for water-in-oil emulsions.

In view of what has been said previously, it hardly appears necessary to give further directions as to the manufactureof the product herein contemplated as a new composition of matter, and particularly as a demulsifier for petroleum emulsions of the water-in-oil type. However, for purposes of convenience, the following is included:

Omyalicylated triricinoleinE.rampZe 1 One pound mole of triricinolein in the form of castor oil is treated with three pound moles of ethylene oxide in the manner previously described.

OryuZ-kylated triricinoleinE.rample 2 Oasyalkylated triricinolein-Erample 3 The same procedure is followed as in oxyalkylated triricinolein, Example 1, preceding, except that nine moles of ethylene oxide are employed instead of three moles.

Composition of matter-E:rample 1 One thousand pounds of water-insoluble oxyalkylated triricinolein of the kind exemplified by Example 1, preceding, is placed in an oxidation Vessel, so that the depth of reactant through which air is forced, is at least 3 feet, and steam coils are used so as to maintain a temperature of approximately 115 t 130 C. No. catalyst is added. The incoming air is distributed through a connection with a suitable number of small openings. Air is passed through at a rate so as to obtain uniform distribution and complete contact with the mass to be oxidized. The material is oxidized for a period of times varying from 300 hours to 500 hours, but, in any event, oxidation is stopped at a point short of stringyness or incipient rubber-like character. Other conventional oxidation procedures of the kind employed in the oxidation of castor oil may be list if desired.

Composition of matter-Example 2 The .same procedure is followed as in comp sition of matter, Example l,"preceding, exce that one employs an oxylkylated triricinolein the kind exemplified by Example 2, precedir instead of the kind described under Example preceding.

Composition of matterEa:ampZe 3 The same procedure is employed as in cor position of matter, Example 1, except that o employs'an oxyalkylated triricinolein of the ki: exemplified by Example 3, preceding, instead the kind described under Example I, precedii Conventional demulsifying agents employed the treatment of oil field emulsions are used 20 such, or after dilution with any suitable solve:

such as water; petroleum hydrocarbons, such gasoline, kerosene, stove oil, a coal tar produ such as benzene, toluene, xylene, tar acid cresol, anthracene oil, etc. Alcohols, particula: aliphatic alcohols, such as methyl alcohol, eti alcohol, denatured alcohol, propyl alcohol, bu alcohol, hexyl alcohol, octyl alcohol, etc.,- in be employed as diluents. Miscellaneous solven such as pine oil, carbon tetrachloride, sulfur 1 oxide extract obtained in the refining of 1: troleum, etc., may be employed as diluen Similarly, the material or materials herein c scribed may be admixed with one or more of t solvents customarily used in connection w: conventional demulsifying agents, provided tl such compounds are compatible. They will compatible with the hydrophile type of solve in all instances. Moreover, said material or rr terials may be used alone, or in admixture w; other suitable well known classes of demulsil ing agents.

It is well known that conventional demulsii ing agents may be used in awater-soluble for or in an oil-soluble form, or in a form exhib ing both oil and water solubility. Sometin they may be used in a form which exhibits reI tively limited oil solubility. However, since Si. reagents are sometimes used in a ratio of 1 10,000, or 1 to 20,000, or even 1 to 30,000, st an apparent insolubility in, oil and water is 1 significant, because said reagents undoubtei have solubility within the concentration e ployed. This same fact is true in regard to 1 material or materials herein described.

We desire to point out that the superiority the reagent or demulsifying agent contempla in our herein described process for breaking 1 troleum emulsions, is based upon its ability treat certain emulsions more advantageously a at a somewhat lower cost than is possible w other available demulsifiers, or conventional in tures thereof. It is believed that the particu desmulsifying agent or treating agent herein 1 scribed will find comparatively limited applll tion, so far as the majority of oil field emulsii are concerned; but we have found that sucl demulsifying agent has commercial value, a: will economically break or resolve oil field em sions in a number of cases which can not treated as easily or at so low a cost with 1 demulslfying agents heretofore available.

In practising our improved process for resc ing petroleum emulsions of the watenin-oil ty a treating agent or demulsifylrig agent of m kind above described is broughtihto contact w or caused to act upon the emulsion to be treated, in any of the-various ways, or by any of the various apparatus now generally used to resolve or break petroleum emulsions with a chemical reagent, the above procedure being used either alone, or in combination with other demulsifying procedure, such as the electrical dehydration process.

The demulsifier herein contemplated may be employed in connection with what is commonly known as down-the-hole procedure, i. e., bringing the demulsifier in contact with the fluids of the well at the bottom of the well, or at some point prior to their emergence. This particular type of application is decidedly feasible when the demulsifier is used in connection with acidification of calcareous oil-bearing strata, especially if suspended in or dissolved in the acid employed for acidification.

Having thus described our invention, what we claim as new and desire to secure by Letters Patent is:

1. A process for breaking petroleum emulsions oi the water-in-oil type, characterized by subjecting the emulsion to the action of a demulsifying agent comprising a drastically oxidized water-insoluble oxyalkylated triricinolein.

2. A process for breaking a petroleum emulsion of the water-in-oil type, characterized by sub jecting the emulsion to the action of a demulsifying agent comprising a drastically oxidized water-insoluble oxyethylated triricinolein.

3. A process for breaking a petroleum emulsion of the water-in-oil type, characterized by subjecting the emulsion to the action of a demulsifying agent comprisinga. drastically oxidized water-insoluble oxyethylated castor oil; the oxyethylation of said castor oil involving at least three and not more than nine moles of ethylene omde for each mole of triricinolein employed prior to oxidation.

MELVIN DE GROOTE. BERNHARD KEISER. 

